Lens abrading machine



July l, 1941. 1 w. GODDU LENS ABRADING MACHINE Filed Jan. 18, 1939 4Sheets-Sheet 2 ATT NEY.

July 1, 1941.

L. W. GODDU LENS ABRADING MACHINE Filed Jan. 18, 1939 4 Sheets-Sheet 3July l, 1941. W, GQDDU '2,247,706

LENS ABRADING MACHINE Filed Jan. 18, 1939 4 Sheets-Shee 44 INVENTOR. mvo/f/ 60am/ B Patented July 1, 1941 2,247,706 y LENS ABRADING MACHINELloyd W. Goddu, Southbridge, Mass., assigner to American QpticalCompany,

Southbridge,

Mass., a voluntary association of Massachusetts Application January 18,1939, Serial No. 251,541

Claims. (Cl. 5ll2i) rIhis invention relates to improvements in surfacingmachines and has particular reference to a machine for surfacingophthalmic lenses or analogous Work.

One of the principal objects of the invention is to provide improvedmeans for controlling the pressure on the lens or work during thesurfacing operation.

Another object is to provide improved means for surfacing curvedsurfaces wherein the operating parts will be simple, inexpensive andpositive in their function.

Another object is to provide a machine of the above character withself-contained power generating means and simplified speed controllingmeans.

Another object is to provide a compound lever arrangement for regulatingthe pressure on the work or lens during the surfacing operation.

Another object is to provide novel means for holding the work guidingmeans in operative or inoperative position.

Other objects and advantages of the invention should become apparentfrom the following description taken in connection with the accompanyingdrawings and it will be apparent that many changes may be made in thedetails of construction and arrangement of parts without departing fromthe spirit of the invention as expressed in the accompanying claims. I,therefore, do not wish to be limited to the exact disclosures made asthe preferred form only has been given by way of illustration.

Referring to the drawings:

Fig. I is a front elevation of the machine embodying the invention;

Fig. II is a side elevation of said machine showing the means forcontrolling the pressure on the work in operative position;

Fig. III is a plan view of said device; and

Fig. IV is a fragmentary side elevation showing the work guiding leverand pressiue control means in inoperative position.

Machines of the character described are adapted particularly for use informing spherical surfaces and are used primarily for forming highlypolished surfaces.

Several different arrangements have been provided in the past forcontrolling the pressure on the work during the surfacing operation. Inmost commercial machines a spring pressed plunger was used incombination with means for varying the tension of the spring and therebycontrolling the pressure exerted on the Work or lens during thesurfacing operation. Such arrangements, due to the variation of thesurface curvatures being generated, and through the movement cf the workor lens from a high to a low spot on the face of the tool, cause thepressure to be uneven. It is apparent that when a spring pressure isused and when the work is moved to a high position on the tool thetension of the spring will be increased beyond that which exists whenthe work or lens is moved to a low position on the tool. Such deviceswere also quite complicated and expensive in structure.

One of the primary objects, therefore, of the present invention is toovercome the above undesirable feature by the provision of relativelysimple and inexpensive means whereby the pressure on the work or lensmay be quickly and easily controlled and with which the said pressurewill be substantially equal throughout all positions of movement of thework or lens during the surfacing operation,

Referring more particularly to the drawings, wherein like characters ofreference designate like parts throughout the several views, the deviceembodying the invention comprises broadly a base i having a toolsupporting spindle 2 adjacent one end thereof and a compound lever 3pivotally attached to a stud e adjacent its opposite end.

The spindle 2 is threadedly connected at 5 to the stud shaft of asuitable gear reduction assembly il driven by a motor l. A bowl 8 isalso connected, as by screws or other means 9, to a flange it on theadjacent threaded end 5 of the stud shaft. The bowl 8 and spindle 2 areadapted to be simultaneously rotated by the motor 'l through the gearreduction i5. A tool il having the desired surface curvature l2 thereon,which is to be formed on the work or lens E3, is attached to the spindle2 and is adapted to be rotated therewith.

The work or lens i3 is attached to a suitable block ill by pitch, orother holding means such as adhesive or mechanical means. The block rlil has a .tapered depression l5 in its upper sur- 'Ihe holding deviceI9, as illustrated in Figs.

I, II .and III, lconstitutes a boltlike member 2I which extends througha slot 22V in the end of the arm 2U, The vboltliike member ZI has ahea-d 23 provided with a perforation in a sleeve 24 which f1ts over saidhead 23 in which the rod I8 extends. The opposite end of the bolt 2| isthreaded and is provided with -a suitable clamp nuit 25.

The above arrangement provides means whereby the rodlike member I8 maybe adjusted longitudinally in the aligned openings in the head 23 andsleeve 24 .and may be seit to different angular positions or move-d todilerent positions longitudinally of the slot 22 in the arm 20. .en

eccentric adjustment may also be imparted Ato the pin I1, :due to thelateral or ofi-center portion 49 of the rod I8. The above adjustmentsare accomplished by loosening the nut 25 which allows the rod I8 to beslid freely within the aligned openings in the head 23 and sleeve 24 andwhich also allows the bolt 2l .to be rotated in or moved longitudinallyof the slot 22. When in desired adjusted position the nut 25 istightened causing the head 23 to be drawn inwardly of the sleeve 24tending to move the normally aligned openings in s-aid head 23 andsleeve 24 out .of alignment and thereby cause the walls of said openingsto grip and hold the rod I8 in adjusted position. This adjustment alsosimultaneously moves the inner face of the sleeve 24 into engagementwi-th the side surface of the arm 20 and thereby locks the bolt 2l`against rotation and against movement relative to said arm.

The arm 2i) lis of a substantially S shape having a kbifurcated portion26 pivoted at 21 to a sleeve 28. The sleeve 23 is rotatably supported onthe stud 4. Suitable spaced needle bearings 29 and 30 are provided topermit free rotar; movement of the sleeve 28 on said stud. Thebifurcated portion, adjacent its base, is provided with alignedvertically extending slots 3l. The slots 3l each have 'an offset portion32 adjacent their upper end Vand an offset portion 33 :adjacent theirlower end. The opposite walls of the slots are provided with .a recess34. The function of said osets andrecess will be described hereinafter.

A lever 35 of the rst kind is pivoted at 35 to Van arm 43 extending fromthe sleeve 28 and lying between the branches of the bifurcated portion23. The lever 35 has a link member 31 pivot-ally connected thereto, .asillustrated at 38. The lever 35 has a troughlike end 39 in which aweight 45 is slidably supported. The link 31 is positioned between thebranohesof the bifurcated portion 26 and has an opening adjacent itsupper end in which a pin 4I is adapted to be fitted by extending thesaid pin through the slots 3|,

When the pin 4I is positioned in the off-set 33, as illustrated in Fig.IV, the arm 20 is hel-d in a raised position away from the surfacingtool II. It is to be noted that when in this position the lever 35 isresting upon the upper end of the stud 4.

When the pin 4I is in the offset 32, Aas shown in Fig..II, the lever 35is raised so that the action of gravity Von the weight '43 will betransmitted through the link connection 31 VtoV the arm 20 causing thesaid arm .to move downwardly about its pivotal connection 21 under theaction of the weight .40. This lcauses thepin IB to 'exert a pressure onthe lens or work I3 during the surfacing operation. The amount ofpressure may be varied by movement oftthe weight 4I) longitudinally ofits troughlike support 39. It is apparent that when the weight 40 ismoved toward the pivotal connection 33 the weight or downward pull onthe lever arm 20 will be decreased and vice versa. It should be notedthat the n'ature of the lever arrangement allows a much less cumbersome:an-d heavy Weight `t-o be used without changing the effect on thespindle I8 than if a direct leverage was used. This leverage provides .aratio of approximately one to iive between the weight and the spindlepressure. This ratio is varied yas the weight 4!! i-s moved along `thetrough 39. It Iis also noteworthy that the use lof `a weight andleverage gives a constant pressure on the lens at all times during thegrinding or surfacing of a lens.

To obtain the initial required length of the pin I3 to clause the lever35 and weight 40 to assume th-e desired angular position and clearancefrom `the end of the stud 4, the pin 4I is position-ed in the recess 34.This holds the arm 2B at the desired height when the lever 3971s restving upon the upper end of the stud 4.v The nut 25 is then loosened andthe pin I8 adjusted to position i'ts tapered end I6 in the recess I5 ofthe block. The said pin vis simultaneously a'djusted 'to the desiredangle, and to the vdesired oli-center position. Referring to thedesire-d angl-e mentioned above, it is usually most desirable t-o linethe pin i3 radially with the center of curvature of the lap curvatureI2. When adjusted to Vdesired position the nut 25 is tightened to holdthe pin I8 in positive fixed rel-ation with the arm '23. The lever 35and weight 40 is then raised an amount sufficient to Aallow the pin I8to be lin positive fixed relation with 'the arm 23. The lever 35 andweigh-t 43 is then raised an amount sufficient to allow the pin 4I,oarried by the upper end of the link 31, to be posi'tio-ned in theoffset 32. This cau-ses the Weight 43 to exert a pressure on the lever35, which pressure is transferred through the link 31 to the arm 20.

The arm 46 is provided with an intermediate slotted portion havingspaced surfaces 42. A suitable ball bearing 43 is mounted on aneccentric shaft 44, as illustrated in Figs. II and III. The shaft 44 isdriven by a suitable reduction gear system contained in a housing 45 andoperated by the motor 1.

The reduction gear system contained in the housing 6 and which is alsodriven by the motor 1 is such as to rotate the surfacing tool Il at amuch greater speed than the speed of rotation of the eccentric 44 asbrought about by the gearing in thehousing 45. The difference betweenthe ratio of speeds is approximately 6 to 1. It is to be understood,however, that these ratios may be Varied and controlled. Y

Rotation of the eccentric 44 through the reduction gearing in thehousing 45 causes the arm 20, pivotally connected to the sleeve 28, tobe oscillated in a direction transversely of the surfacing tool I I. Theamount of oscillation is such as to cause the lens or work I3 to movetransversely of the tool during the rotation of said tool an amountsuioient to surface the entire surface of the work or lens in engagementwith said tool.

The gearings in the housings E and 45 are not shown because they are ofthe conventional commercial type; the only difference being, in thisparticular instance, that the two sets of gearing are driven by a singlesource of power.

The operation of the device lis substantially as follows:

The work or lens I3 to be surfaced is secured to a suitable holder orblock I 4 by a layer of pitch or other desirable adhesive or mechanicalholding means. A surfacing tool Il having the desired surface curvatureon the face I2 thereof, which is to be formed on the work or lens I3, isplaced on the spindle 2. A suitable tapered connection between the shaft2 and tool automatically locks the tool in desired centered position.

The pin 4I is then positioned in the recess 3d of the arm 28 so as tocause the said arm to be locked in an initial set position. VThe pin Itis then adjusted to position the tapered end thereof in engagement withthe block Il within the recess I5. The pin supporting means is thenadjusted longitudinally of the slot 22 to vary the effective length ofthe arm 26 or the distance between the tapered end I8 and the axis ofrotation of the sleeve 28, of the stud Il. This adjustmentlongitudinally of the slot 22 increases or decreases the arc of the lineof movement of the work or lens I3 in a direction transversely of thetool. The pin supporting means is then adjusted longitudinally of itselfand rotated to provide the desired eccentric position. When in desiredadjusted position the nut 25 is tightened to secure the pin in adjustedposition. The lever 35 is then raised to position the pin 4I within theoffset 32 an-d in engagement with a hooklike shouldered surface 41 insaid offset. The weight d@ is then adjusted longitudinally of itstroughlike support 39 to regulate the pressure on the work or lens I3during the surfacing operation.

Power is then directed to the motor 'I by means of a switch or othersuitable means 33 connected with a suitable source of energy. Rotationof the motor 'I causes the spindle 2 and tool I I carried thereby to berotated at a given speed controlled by the reduction gearing in thehousing S and simultaneously causes the eccentric 44 to be rotated atthe desired speed controlled by the gearing in the housing 45. Asuitable surfacing or polishing compound is applied tc the surface I2 ofthe surfacing tool during the surfacing operation. This may be in theform of a liquid mixture of rouge or the like which may be poured on tothe face of the tool.

It may be pointed out that the weight 4G, adjustably positioned on thelever 35 in the trough 39, lies substantially directly over the leversystem pivot 4. This provides a swinging lever system with noappreciable inertia and greatly reduces wear due to pressure andvibration,

From the foregoing description it will be seen that simple, erlicientand economical means and method have been provided for accomplishing allof the objects and advantages of the invention.

Having described my invention, I claim:

l. In a device of the character described, the combination of a basehaving a tool rotatably supported adjacent one end thereof and workholding means adapted to receive a piece of work for engagement withsaid tool, a sleeve pivotally supported adjacent the opposite end ofsaid base, a projection on said sleeve, an arm pivotally connected tosaid sleeve for pivotal movement about an axis substantially normal tothe axis of rotation of said sleeve, a work holder engaging member onsaid arm, a lever pivotally connected to the projection on said sleeve,a link connecting said lever to said arm, weight means on said lever forcausing the arm to be urged under the pressure of said weight toward thesurfacing tool and means for relieving the pressure of said weight onsaid arm and for holding said arm out of operation.

2. In a device of the character described the combination of a basehaving means for supporting a tool, means for holding work on said tool,a lever having a pivotal connection with said base for movement towardand away from the tool and for movement in a direction substantiallynormal to said rst movement and across the face of the tool, a controlmember mounted to follow said normal movement, said lever hav-- ingmeans adjacent its end opposite its pivotal connection for engaging theWork holding means, a second lever pivotally supported on said conltrolmember intermediate the ends of said first lever, said second leverhaving means connecting said second lever with said rst lever at a pointremoved from the pivotal connection of said second lever and a weightsupported by said second lever for movement longitudinally thereof.

3. In a device of the character described the combination of a basehaving a tool supported thereon, a Work holding mema'ber adapted toreceive a piece of work for engagement with said tool, a sleevepivotally supported on said base at a point spaced from the tool, an armpivotally connected to said sleeve for pivotal movement about an axissubstantially normal to the of rotation of said sleeve, a work holderengaging member on said arm adjacent its end opposite its pivotalconnection with said sleeve, a projection on said sleeve extending inthe direction of said arm, a lever pivotally connected to the projectionat a point intermediate the ends of said arm, a link connecting saidlever to said arm at a point removed from the pivotal connection of saidlever with said projection and weight means on said lever movablelongitudinally thereof toward and away from the pivotal connection ofthe arm with said sleeve.

4. In a device of the character described the combination of a basehaving means for supporting a tool, means for holding work on said tool,a lever having a pivotal connection with said base for movement towardand away from the tool and for movement in a direction substantiallynormal to said first movement and across the face of the tool, saidlever having spaced engagement portions intermediate its ends and meansadjacent its end opposite its pivotal connection for engaging the Workholding means, a control member mounted to follow said normal movement,a second lever pivotally supported on said' control member intermediatethe ends of said first lever, said second lever having means selectivelyengageable with the engagement portions of the rst lever for connectingsaid second lever with said first lever at a point removed from thepivotal connection of said second lever and a weight supported by saidsecond lever for movement longitudinally thereof.

5. In a device of the character described the combination of a basehaving a tool supported thereon, a sleeve pivotally supported on saidbase at a point spaced from the tool, an arm pivotally connected to saidsleeve for pivotal movement about an axis substantially normal to theaxis of rotation of said sleeve, a work holder engaging member on saidarm adjacent its end opposite its pivotal connection with said sleeveand vertically spaced engagement portions located intermediate the endsof the arm, a projection on said sleeve extending in the direction ofsaid arm, a lever'pivotally connected to the projection at a pointintermediate the ends of said arm, a link on said lever for selectivelyconnecting said lever to said spaced engagement portions of said arm atapoint removed from the pivotal connection of said lever with saidprojection and Weight, means on said lever movable longitudinallythereof toward and away from the pivotal connection of the arm with saidsleeve, the connection of said link with one of said engagement portionsof the armbeing adapted to cause said arm to receive the pressure actionof the weight and the connection of the link with the other of saidengagement portions being adapted to relieve the arm from the pressureaction of the Weight and beingadapted to hold said arm away from thetool.

6. In a device of the character described the combination of a basehaving means for supporting a tool, work holding means adapted toreceive a piece of work for engagement with said tool, a lever having apivotal connection with said base for movement toward and away from thetool and for movement in a direction substantially normal to said firstmovement and across the face of the tool, said lever having meansadjacent its end opposite the pivotal conneotion for engaging the workholding means, a control member mounted to follow said normal movement,a second lever pivotally supported on said control member intermediatethe ends of said first lever, said second lever having means connectingsaid second lever with said first lever at a point removed from thepivotalconnection of said second lever, a weight supported by saidsecond lever for movement longitudinally thereof and means incooperative relation with said levers for imparting controlledl movementof the rst lever in a direction transversely of the tool,

7. In a device of the character described the combination'of a basehaving a tool supported thereon, work holding means adapted to receive apiece of Work for engagement with Isaid tool, a sleeve` pivotallysupported on said base at a point spaced from the tool, an arm pivotallyconnected to said sleeve for pivotal movement about an axissubstantially normal to the axis oi rotation dof said sleeve, a workholder engaging member onsaidvV arm adjacent its end opposite itspivotal connection with said sleeve, a projection on said sleeveextending in the. direction of said arm, a lever pivotally connected'tothe projection at a point intermediate the ends of said arm, a linkconnecting said lever to said arm at a point removed from the pivotalconnection of said lever with said projection, weight means on saidlever movable longitudinally thereof toward and away from the pivotalconnection of the arm with said sleeve, and means engagingsaidprojection for moving said projection and levers in a directiontransversely of the tool.

8. In a device of the character described the combination of a hollowbase, a tool support rotatably mounted on said hollowV base, a tool onsaid tool support, work holding means adapted to receive a piece of Workfor engagement with said tool, a sleeve pivoted to said base about averti` cal axis spaced from the tool support, a first lever pivoted tosaid sleeve aboutJ a'horizontal axis, said lever having means adjacentits end opposite its pivotal connection with said sleeve for holdingWork in engagement with the tool, said first lever having verticallyspaced engagement v otally connected to said second lever at a pointremoved from the pivotal connection of said second lever with theprojection, said link having a portion adapted to be engaged with eitherof the spaced engagementrportions of said first lever and a weightsupported on said second lever for movement longitudinally thereoftoward and away from the pivotal connection of the sleeve to the base.

9. In a device of the character described the combination of a hollowbase, a tool support ro-V tatably mounted on said hollow base, a tool onsaid -tool support, work holding `means adapted to receive a piece ofWork for engagement with said tool, a sleevepivoted to said base about avertical axis spaced from the tool support, a

first lever pivoted toy said sleeve about a horizontal axis, said leverhaving means adjacent its end opposite its pivotal connection with saidsleeve for holding work in engagement with said tool, said rst leverhaving vertically spaced engagement portions intermediate the endsthereof, a projection on said sleeve extending in the direction of saidrst lever, cam means mounted on said base for engagement with saidprojection, a second lever pivoted to said projection Vand extendingfrom said pivotal connection in a di` rection toward the pivotalconnection ofthe sleeve With said base, a link pivotally connected tosaid second lever at a point removed from the pivotal connection of saidsecond lever with the projection, said link having a portion adapted tobe engaged with either of the spaced engagement portions of said rstlever and means internally of said base having a driving connection withthe tool support for rotating said tool and having a driving connectionWith said cam means yengaging said projection on said sleeve forrotating said cam to impart an oscillatory movement to said projectionand to the levers associa-ted with said projection for moving said iirstlever in a direction transversely of the tool.

10. In a device of the character described, the combination of a basehaving mounted thereon a tool support, a cam member, a horizontally andvertically pivoted lever, and a control member mounted to follow thehorizontal movement of said lever, an abrading -tool on said support,work holding means adapted to receive a piece of work for engagementwith said tool, said control member having a portion in operativeengagement with said cam, said lever having Aa portion for supportingwork on said tool, a second lever member pivotally supported on saidcontrol member and intermediate the ends of the rst lever and having anadjustable weight at one end thereof, a link member connecting saidlevers at a point removed fromthe pivot of the second lever, spacedengagement portions on said rst lever for engaging :the said link memberand thereby hold the levers in desired positions relative to each other,and means for actuating the said tool support and cam member wherebysaid cam member acts on said leversto 'cause them to oscillatetransversely relative to the tool.

LLOYD W. GODDU.

